Fuji GA645 Film advance question

Sometimes with my Fujifilm GA645, when I shoot the final frame, the film advance starts and advances all the film onto the right spool. However, it does not shut off and keeps spinning endlessly until I open up the back. This only happens sporadically. What is the method the camera detects that all the film has been advanced and then shuts off. Can I fix this part of the camera so that it does not keep advancing endlessly?

Sometimes with my Fujifilm GA645, when I shoot the final frame, the film advance starts and advances all the film onto the right spool. However, it does not shut off and keeps spinning endlessly until I open up the back. This only happens sporadically. What is the method the camera detects that all the film has been advanced and then shuts off. Can I fix this part of the camera so that it does not keep advancing endlessly?

Thanks!

Surely the film advance mechanism in this camera is not so different from others. Anyone have any idea what I can do to stop the film from spinning endlessly? There must be some simple contact that is not right but I dont understand how this whole thing works.

In trying to ascertain an answer to your question, I forgot that my GA645zi had a roll of Portra 220 in it.

Nuts.

No, there isn't a contact that you can just clean off. Yes, it's similar to others in that it has a motor advance, but under the covers they're all different in there. Yours might just need something internal cleaned off, but it has to be opened up by a technician. I know that there's somebody in the US who does some repairs to these, as I have seen his name mentioned on the forum. You'll have to do a bit of a search for it.

The mechanism appears to be strictly internal, with the internal computer keeping track of film position and the rest of it. It's not like these are a TLR, with a mechanical counter. Very likely there's some dust or atmospheric film on a sensor in there. Or corrosion between the last frame "beep" circuit and the counter. Just guessing, but it's all "not repairable this station."

In trying to ascertain an answer to your question, I forgot that my GA645zi had a roll of Portra 220 in it.

Nuts.

No, there isn't a contact that you can just clean off. Yes, it's similar to others in that it has a motor advance, but under the covers they're all different in there. Yours might just need something internal cleaned off, but it has to be opened up by a technician. I know that there's somebody in the US who does some repairs to these, as I have seen his name mentioned on the forum. You'll have to do a bit of a search for it.

The mechanism appears to be strictly internal, with the internal computer keeping track of film position and the rest of it. It's not like these are a TLR, with a mechanical counter. Very likely there's some dust or atmospheric film on a sensor in there. Or corrosion between the last frame "beep" circuit and the counter. Just guessing, but it's all "not repairable this station."

Thanks for your reply. OK, my guess was wrong on how this film advance works. No worry. As far as problems goes, this is very minor, barely even qualifying as a problem. Once I see that the film advance is never going to stop, I just pop open the camera back. This stops the film advance and I can continue on as normal. Loading the camera works perfectly as does shot-to-shot film advance.

I know the guy you are talking about in the US who repairs these cameras. I'm in China and have other venues to get this done if I so choose.